Windfarm Foundation Design
Ground Improvements for Wind Turbines, Tararua Ranges, New Zealand
TGE were engaged to design ground improvements for a wind turbine located in a swampy area underlain by soft clays and silts.
The wind farm, at an elevation of approximately 450m above sea level, was constructed predominantly on weathered and shattered greywacke rock. However, one of the turbines was located within a deep pocket of soft alluvial soils which, over time, had been uplifted from the valley below by seismic activity.
TGE were tasked with the design of ground improvements at this site to provide the same stiffness and capacity as the rest of the turbines founded on weathered rock. TGE was able to identify a number of options in collaboration with the Contractor and a pattern of rigid inclusions was adopted.
The design required high quality sampling and lab testing of the soft soils to accurately model the soil-structure interaction. TGE then developed a detailed finite element model to progress the chosen option through to detailed design.
